A Drude-model approach to dispersion interactions in dipole-bound anions

A one-electron model potential for calculating the binding energy of an exc ess electron interacting with polar molecules and their clusters is describ ed. The unique feature of this potential is the treatment of polarization a nd dispersion effects by means of a Drude model. The approach is tested by calculating the energies for binding an excess electron to HCN, (HCN)(2), H NC, and (HNC)(2). The model potential results are found to be in good agree ment with the predictions of high-level all-electron calculations. (C) 2001 American Institute of Physics.